Power wheelchair with clutch control device

Abstract

A power wheelchair includes a pair of clutches, each coupled to a respective drive power source and a respective drive wheel, and a clutch control device that includes a pair of rod pivoting units, a control unit, and a flexible linking unit interconnecting the control unit and the rod pivoting units. The rod pivoting units are coupled to rotary control rods of the clutches, respectively. By operating the control unit, drive power transmission of the clutches can be controlled accordingly.

1 . A power wheelchair comprising: 
 a chair frame including a pair of spaced apart lateral frame parts;    a pair of clutches, each of which is mounted on a respective one of said lateral frame parts of said chair frame and includes a rotary control rod;    a pair of drive power sources, each of which is coupled and supplies drive power to a respective one of said clutches;    a pair of drive wheels, each of which is coupled to and driven by a respective one of said clutches; and    a clutch control device including 
 a pair of rod pivoting units, each of which has 
 a rod coupling member coupled to said rotary control rod of a respective one of said clutches, and operable so as to rotate said rotary control rod of the respective one of said clutches between a first clutch position, in which the respective one of said clutches permits transmission of the drive power from the respective one of said drive power sources to the respective one of said drive wheels, and a second clutch position, in which the respective one of said clutches is inhibited from transmitting the drive power from the respective one of said drive power sources to the respective one of said drive wheels, and  
 a restoring component coupled to said rod coupling member for accumulating a restoring force to restore said rotary control rod of the respective one of said clutches from the second clutch position to the first clutch position,  
 
 a control unit mounted on said chair frame and operable between first and second control states, and  
 a flexible linking unit interconnecting said control unit and said rod coupling members of said rod pivoting units such that said rotary control rods of said clutches are disposed at the first clutch position when said control unit is at the first control state, and at the second clutch position when said control unit is at the second control state.  
   
   
   
       2 . The power wheelchair as claimed in  claim 1 , wherein said clutch control device further includes a pair of contact switches, each of which is disposed adjacent to and is triggered by said rod coupling member of a respective one of said rod pivoting units to generate a disable signal for a corresponding one of said drive power sources when said rotary control rod coupled to said rod coupling member is moved to the second clutch position.  
   
   
       3 . The power wheelchair as claimed in  claim 2 , wherein said rod coupling member of each of said rod pivoting units includes a sleeve part coupled co-rotatably to said rotary control rod of the respective one of said clutches, a guide part connected to said sleeve part and further connected to said flexible linking unit, and an actuator part projecting outwardly from said sleeve part and disposed to trigger the respective one of said contact switches when said rotary control rod coupled to said rod coupling member is moved to the second clutch position.  
   
   
       4 . The power wheelchair as claimed in  claim 3 , wherein each of said lateral frame parts of said chair frame is provided with a respective mounting plate, said clutches being respectively disposed under said mounting plates of said lateral frame parts, said rotary control rods of said clutches extending respectively and upwardly through said mounting plates of said lateral frame parts, said sleeve parts of said rod coupling members of said rod pivoting units being respectively disposed above said mounting plates of said lateral frame parts, said contact switches being mounted respectively on said mounting plates of said lateral frame parts.  
   
   
       5 . The power wheelchair as claimed in  claim 3 , wherein said restoring component of each of said rod pivoting units is sleeved on said sleeve part of said rod coupling member, and has an anchoring end anchored to said mounting plate on a respective one of said lateral frame parts, and a restoring end opposite to said anchoring end, 
 each of said rod pivoting units further including an end cap coupled to said restoring end of said restoring component, and a fastener for fastening said end cap to said sleeve part of said rod coupling member such that said restoring end of said restoring component is rotatable together with said end cap and said rod coupling member relative to said anchoring end.    
   
   
       6 . The power wheelchair as claimed in  claim 1 , wherein said flexible linking unit includes a pair of flexible components, each of which extends between said control unit and said rod coupling member of a respective one of said rod pivoting units.  
   
   
       7 . The power wheelchair as claimed in  claim 6 , wherein said rod coupling member of each of said rod pivoting units includes a sleeve part coupled co-rotatably to said rotary control rod of the respective one of said clutches, and a guide part connected to said sleeve part and further connected to the respective one of said flexible components of said flexible linking unit, said guide part being formed with a curved guide groove for guiding the respective one of said flexible components.  
   
   
       8 . The power wheelchair as claimed in  claim 7 , wherein each of said lateral frame parts of said chair frame is provided with a respective mounting plate, said clutches being respectively disposed under said mounting plates of said lateral frame parts, said rotary control rods of said clutches extending respectively and upwardly through said mounting plates of said lateral frame parts, said sleeve parts of said rod coupling members of said rod pivoting units being respectively disposed above said mounting plates of said lateral frame parts.  
   
   
       9 . The power wheelchair as claimed in  claim 7 , wherein said restoring component of each of said rod pivoting units is sleeved on said sleeve part of said rod coupling member, and has an anchoring end anchored to said mounting plate on a respective one of said lateral frame parts, and a restoring end opposite to said anchoring end, 
 each of said rod pivoting units further including an end cap coupled to said restoring end of said restoring component, and a fastener for fastening said end cap to said sleeve part of said rod coupling member such that said restoring end of said restoring component is rotatable together with said end cap and said rod coupling member relative to said anchoring end.    
   
   
       10 . The power wheelchair as claimed in  claim 1 , wherein said control unit of said clutch control device includes: 
 a control base mounted on said chair frame;    a control lever connected to said flexible linking unit; and    a pivot axle that mounts pivotally said control lever to said control base such that said control lever is operable to dispose said control unit at a selected one of the first and second control states.    
   
   
       11 . The power wheelchair as claimed in  claim 10 , wherein said control base includes a pair of spaced apart pivot lugs, each of which has a lever engaging edge formed with a pair of first and second engaging grooves that are angularly spaced apart from each other relative to said pivot axle, 
 said first engaging grooves of said pivot lugs engaging removably said control lever when said control unit is disposed at the first control state,    said second engaging grooves of said pivot lugs engaging removably said control lever when said control unit is disposed at the second control state.    
   
   
       12 . The power wheelchair as claimed in  claim 11 , wherein said control lever includes: 
 a tube body having a tube wall with opposite first and second tube ends, said first tube end being mounted pivotally to said pivot lugs by said pivot axle, said tube wall being formed with a guide slot unit along a length thereof;    a guide body connected to said first tube end and further connected to said flexible linking unit;    a pull rod movably disposed in said tube body;    a locking pin extending through said pull rod and said guide slot unit and movable along said guide slot unit;    a biasing member for biasing said pull rod toward said pivot axle to enable said locking pin to engage a selected pair of said first and second engaging grooves of said pivot lugs; and    a handle disposed outwardly of said tube body and proximate to said second tube end, connected to said pull rod, and operable so as to pull said pull rod against biasing action of said biasing member for disengaging said locking pin from said first and second engaging grooves.